SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9024bb51077f15c7a589005b936c325f012b7a259333a943ee510be09c8068da' 
  AND token = 'B/BLc5gpfxhWXxX5ke6sCODMiMLz9dT0V3nh1guWI0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}